1. Field of the Invention
The present invention relates to a semiconductor memory apparatus.
2. Description of the Prior Art
Generally, a semiconductor memory apparatus outputs data stored therein when an address signal and a reading signal are inputted thereto. On the other hand, most of the semiconductor memories are general-purpose products which are compatible with one another even though made by different manufacturers.
For these reasons, it is easy to find out what data are stored in a semiconductor memory, so that it may be possible to illegally copy the data stored in the memory to provide it in another apparatus in order that various functions can be used without permission. For example, in the case of the satellite broadcasting for which viewers have to pay, the receivers are programmed so that only contractors can receive the satellite broadcasting. However, the satellite broadcasting can be received without permission by reading out the contents of the memory in which the program is stored, copying them to another memory and providing the memory in a receiver. Such an illegal use can also be made in the case of apparatuses such as game apparatuses.